The invention relates to a device for stabilizing a single-track vehicle and also to a single-track vehicle provided with such a device.
Single-track vehicles, for example motorcycles or bicycles, are inherently stable at sufficient travel speed, but on stopping they must be supported by the driver's feet or by means of a supporting device, for instance with runners or supporting rollers, in order to prevent tipping over. On fully-enclosed two-wheeled vehicles, which do not allow foot support because of the bodywork, supporting devices with lateral supporting rollers are known which are raised at higher speeds so that single-track banking turning is possible for travelling at speed. Similar devices are also used on single-track vehicles for disabled people, people of small stature and for learning and test drives. It has also been proposed that the raising of the supporting device for travelling at speed or the lowering thereof for stabilization on stopping be coupled to the speedometer signal and to initiate appropriate actuation automatically at a specific speed or at least to give the driver a warning signal that actuation is required. This simple coupling to the speed signal has not proved successful in practice. In fact, if there is unilateral loading of the supporting device, for instance when turning or in the case of a laterally inclined roadway, then the vehicle can tilt to one side when the supporting device is raised in spite of sufficient speed.
A device of the type referred to in the introduction is known from EP 0 097 623 B1 which comprises in addition to the speedometer a transverse acceleration meter which should prevent raising in the event of unilateral loading or should effect lowering in spite of sufficient speed in the event of increasing transverse acceleration, a sign of imminent tipping. The use of the speedometer signal taking account of the transverse acceleration as a parameter for the raising or lowering of the device has proved a suitable and reliable method of indicating the possibility of actuation to the driver when driving cabin motorcycles. However, it may be regarded as a disadvantage that it is relatively difficult for the driver to become accustomed to the different steering behavior of the vehicle when he raises the supporting device in response to this indication. With lowered supporting rollers, i.e. in multi-track vehicle mode, turning of the steering device in the clockwise direction produces a right turn. With the supporting rollers raised in single-track mode the same actuation of the steering device inclines the vehicle to the left and consequently produces a left turn. Thus automatic actuation of the supporting device is practically ruled out, because the driver can be surprised by this change in the steering behavior and thus there is a danger of actuating the steering device in the wrong direction. Thus this known design is suitable in particular for use in fail-passive systems which prevent incorrect actuations of the supporting device in that for example the raising of the supporting device initiated by the driver is only possible at sufficient travelling speed and without transverse acceleration, and the lowering of the supporting device again initiated by the driver is only allowed under appropriate conditions. However, by comparison with conventional single-track vehicles with foot support this results in changed operating requirements, and a considerable relearning phase is inevitable.